In a withering dissection of "Latin psyche", the embassy in Buenos Aires sent a 17-page advisory to Dublin: a character assassination teed up with an assertion that the locals are psychologically dangerous.

The cable, titled "Understanding Argentina" and dated November 24, 1982, was sent to the secretary of the Department of Foreign Affairs, Iveagh House, Dublin. It was contained in a file marked "travel costs".

It was intended to be an overview of Argentine affairs following a year of turmoil and the country's defeat over the Falklands.

Thirty years later, it reads like an offensive catalogue of stereotypes. The cable states: "As a nation – if they are a nation, and that is part of the pathology – they are morbidly estranged from reality.

"To attempt an exhaustive catalogue of the exotic zoology of serious emotional disorders from which the Argentines collectively suffer would require ample recourse to the early Viennese texts.

"Behavioural aberrations of which they display advanced and frequently simultaneous symptoms include: paranoia, narcissism, aggression, delusions inter alia of grandeur, infantilism, hysteria, exhibitionism, extreme inferiority/ superiority complexes, extravagant self-fantasies, selective amnesia, habitual projection of internal failures on to external agents. Among the few psychological disorders from which the Argentines as a people remain resolutely immune, one may number scrupulosity and compulsive guilt."

On the state itself, the writer said there was some substance to the idea that Argentina's moral shortcomings span from the huge influx of immigrants from southern Italy.

"The mores of Naples and Palermo have certainly infected Argentina," the diplomat wrote.

But here lies the twist, the papers reveal: the underground, criminal counter-culture of the Mafia was not present in Argentina at the time.

"There is no role in Buenos Aires for such heterodox criminality. Here the Mafia is the official culture, the conventional society, the quintessential state," it read.